Closer Examination

The EK-Quantum Surface S360 is a 30-mm thick radiator, which improves compatibility with small form-factor cases and thicker fans, such as the excellent Phanteks T30-120. The "S" in the name stands for slim, which can be somewhat misleading since the width and length of the radiator are above average at 130 mm and 405 mm respectively—this is a thin radiator that makes up room elsewhere for more cooling surface area, and you especially need to account for the length to ensure it fits into your case. The design language is an evolution of the previous EK-Coolstream radiators in that we still see a modular frame, albeit without the fully boxy design with sharp corners that had cut me on a couple of occasions.

The thumbnail for this review is that of the EK-Quantum Surface S360 in white, which goes with the same silver-color anodized aluminium end plate covers, but gets a white paint coat on the steel side plates, too. This so-called black version I have isn't fully black thus, but EK plans to make fully black radiators in addition to selling replacement end plate covers in black sooner than later. Still, you need to be aware of this two-tone design lest you purchase it in black and are surprised when it arrives. The corners are rounder than before courtesy a multi-sided approach I've seen in some of EK's other Quantum-series products, which works well if you go with an all EK-Quantum loop including CPU and GPU blocks.


As is typical for 30 mm class radiators, there are only two BSP G1/4" ports, so both will be plumbed into the loop. They come with pre-installed dust covers you would remove prior to installation. I would have liked multiple ports similar to what Alphacool did with its recently released NexXxos HPE-30, although it appears EK is reserving that for larger radiators. But then I realized something I missed when taking the actual photos, and this is the part where the port on the left in the first image above is slightly lower than on the right. The good thing is it's just a tiny tolerance issue whereby if you have a 9 mm Allen key you can remove the extender fitting and re-tighten it slightly higher up, but the bad thing is this should not have been sent out at all with EK professing Matrix7 compatibility here and there not being the required tool included to do this in the box. The only branding is a glued-on EK badge next to the ports, which won't be visible in most use cases; EK is relying on this design language to speak for itself. Note the four Torx T10 screws per side keeping the frame intact, and you need to remove all eight screws for any modding or replacing of the side/end plates.


The fan holes in the frame are M4 threaded—very well at that, with the side plates getting the aforementioned black paint on this black SKU to better match most PC DIY builds than the native steel color that might arguably have worked better with these end plate covers, similar to the Watercool Heatkiller radiator in the steel finish. These holes are the standard 15 mm apart, which works with just about any case today. There are no screw shields to provide a safety barrier with any screws that are longer than appropriate and might otherwise pierce coolant tubes instead of just fins; however, the fan holes are just offset enough from the tubes not to be damaged either way. In fact, as long as you use the provided screws in a sensible manner with standard 25-mm thick fans, you won't even hurt the fins.


Removing one of the dust cover plugs reveals brass threaded inserts in the brass end tanks, which means the radiator is more than 30 mm at its thickest point after all. It should not affect case compatibility as cases tend to have unencumbered extra space past simply the 360 mm taken up by three 120 mm fans next to each other. The brass extensions have an internal hex head and need to be removed to get the end plate cover out, or to fix any alignment issues as pointed out before. With multi-port versions of this design, you would need to do this to swap it out to where you wish to have the inlet and outlet port, and EK will presumably provide the necessary tool there. I only removed the screws on one side to show you how the frame is set up, with thin steel side plates that are flimsy and the bulky aluminium end plate covers much needed to make these seem more premium than the core is on its own.

The brass extensions are nickel-plated, which will retain the finish over time, unlike the Raijintek CA360 we recently examined that had a patina out of the box. The radiator core adopts the more typical U-flow design for the coolant, with either port as the inlet and the other the outlet depending on your plumbing layout. There is a single row of fins and tube stacks with an incredible 16 tubes that are ~2.0 mm thick and ~15–16 mm tall. This 16-way parallel split of the coolant is far higher than typical for 30-mm thickness class radiator at 12 tubes, and the increased tube width compared to the typical 1.5 mm tubes will also lower coolant flow restriction. If fact, I am curious how the Quantum Surface S360 will fare against some dual-row radiators even, especially those adopting the ultra-thin Black Ice core geometry. EK tries to be creative with marketing by stating the end tanks are composed of brass H62 alloy (62 wt% copper), but then mentioning "Copper H90" for the tubing, which is still brass, but with significantly more copper, of course. Nonetheless, I appreciate the increased transparency compared to those who are way worse in this regard.


The extra width certainly helps accommodate the increased number of tubes, which are also thicker than average, but the biggest reason behind it is the use of shorter fin stacks that are also more in number as a result. This is a page taken out of Hardware Labs' portfolio for providing more heat transfer area. The non-louvered fins that should bolster performance at lower fan speeds and airflow regimes by avoiding local Eddy currents disruptive to radiator cooling are also common between the two. Louvered fins can help at higher flow rates, but these thinner radiators are unlikely to be chart-topping there anyway, so this is my preference, too. The 20 FPI serpentine copper fins complete the puzzle, with my sample measuring in closer to 20 FPI in density to match the rated value. The core itself is ~20 mm thick with a ~5 mm plenum on either side between it and the frame, which is not the easiest to measure given the fins extend slightly past the coolant tubes. Without exactly knowing how thick the fins are, this combination leads me to believe that this radiator will be a low-to-medium-airflow-optimized cooling solution. That having been said, we will see how the radiator fares in our testing over the next couple of pages.